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September Weather in Petersburg, United States

Last updated: June 24, 2025

The average temperature in Petersburg, United States during September rests comfortably at 22°C (73°F). Expect fluctuations as it can dip to a minimum of 8°C (46°F) and soar to a maximum of 34°C (94°F). With 77 mm (3.0 in) of precipitation over 7 days, you might want to pack an umbrella. Additionally, the average humidity level hovers around 69%, creating a warm and slightly muggy atmosphere.

September Temperature in Petersburg

In September in Petersburg, the average temperature is 22°C (73°F). The maximum can reach 34°C (94°F), and the minimum can be as low as 8°C (46°F). This makes Petersburg an ideal destination for travelers seeking a mild climate with the option for both warm days and cooler evenings.

September Weather in Petersburg: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Petersburg, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Petersburg, September typically has an average temperature of 22°C (73°F), with highs reaching up to 34°C (94°F) and lows dropping to around 8°C (46°F).
JanFebMarAprMayJunJulAugSepOctNovDec343847566876797772614540
Data source: Temperature data for Petersburg generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Petersburg

In Petersburg in September, the precipitation amount is 77 mm (3.0 in) over the course of 7 days.

September Precipitation Trends in Petersburg

The chart displays monthly precipitation patterns in Petersburg, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Petersburg, September typically receives around 77 mm (3.0 inches) of precipitation spread over approximately 7 days.
JanFebMarAprMayJunJulAugSepOctNovDec9111714712413712577897710598104
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Petersburg

In Petersburg in September, humidity is 69%. With an average temperature of 22°C (73°F), this humidity feels like a warm embrace, making travel comfortable yet a bit sticky, prompting frequent breaks in the shade and a refreshing drink at hand.

September Average Humidity in Petersburg

This chart illustrates the average monthly humidity levels in Petersburg, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Petersburg is approximately 69%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec87%85%86%84%79%82%79%70%69%76%88%87%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Petersburg

In Petersburg in September, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Petersburg.

Maximum UV Index Levels in Petersburg for September

The chart shows the monthly maximum UV Index (UVI) for Petersburg in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Petersburg typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec3571010111099643
Data source: Petersburg September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How September Weather in Petersburg Compares to Other Months

Weather in Petersburg varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Petersburg, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Petersburg, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather1°C (34°F)91 mm (3.6 inches)87%moderate
February Weather3°C (38°F)117 mm (4.6 inches)85%moderate
March Weather8°C (48°F)147 mm (5.8 inches)86%high
April Weather13°C (56°F)124 mm (4.9 inches)84%very high
May Weather20°C (68°F)137 mm (5.4 inches)79%very high
June Weather25°C (76°F)125 mm (4.9 inches)82%extreme
July Weather26°C (80°F)77 mm (3.0 inches)79%very high
August Weather25°C (77°F)89 mm (3.5 inches)70%very high
September Weather22°C (73°F)77 mm (3.0 inches)69%very high
October Weather16°C (61°F)105 mm (4.1 inches)76%high
November Weather7°C (45°F)98 mm (3.8 inches)88%moderate
December Weather4°C (40°F)104 mm (4.1 inches)87%moderate

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